QuEChERS-气相色谱法测定土壤中毒死蜱残留量的不确定度评定  

作　　者：周丹辉 

机构地区：[1]丹阳市环境监测站,江苏丹阳212300

出　　处：《环境保护与循环经济》2023年第4期74-80,共7页environmental protection and circular economy

摘　　要：采用QuEChERS-气相色谱法对土壤中毒死蜱农药残留量测定的不确定度进行评定。根据方法检测流程建立数学模型,对模型中各参数的不确定度来源进行识别,包括样品测定重复性、标准曲线拟合、添加回收率、标准溶液配制、样品称量和前处理、仪器测定。依据JJF 1059.1—2012《测量不确定度评定与表示》,基于不确定度传播律法,对各不确定度分量进行量化、合成与扩展。在0.1 mg/kg添加水平下,毒死蜱的扩展不确定度为0.0075 mg/kg。毒死蜱在土壤样品中的检测结果在置信概率为95%(k=2)时可表示为0.089±0.0075 mg/kg。影响测定结果不确定度的主要来源为标准溶液配制、标准曲线拟合及添加回收率,提示样品检测过程中需对这几个方面进行严格控制。该研究为QuEChERS-气相色谱测定土壤中毒死蜱农药残留检测方法的改进和检测结果的评价提供了参考。The uncertainty of determination of chlorpyrifos residues in soil using QuEChERS and gas chromatography was evaluated.A mathematical model was established according to the determination process of the experiment,and the uncertainties sources caused by various factors in the model were identified.The sources are mainly the following aspects:repeated determination of samples,fitness of standard curve,recovery rate,standard solution preparation,sample weighing and pretreatment,and measurement of instrument.According to JJF 1059.1-2012 Evaluation and Expression of Uncertainty in Measurement,the source of each uncertainty component was quantified,then all the components were combined and expanded based on law of propagation of uncertainty.The results demonstrated that at the spiking level of 0.1 mg/kg,the expanded uncertainty of measured values of chlorpyrifos was 0.075 mg/kg.The detection result of chlorpyrifos in soil in 95%confidence interval could be expressed as 0.089±0.0075 mg/kg(k=2).The uncertainties of the method were mainly introduced by standard solution preparation,calibration curve fitting and recovery rate,indicating that these aspects should be controlled strictly in the following sample analysis.The study can provide a reference for improving and evaluating the accuracy of QuEChERS-GC method for the determination of chlorpyrifos in soil.

关 键 词：气相色谱法 土壤 毒死蜱 不确定度 

分 类 号：S481.8[农业科学—农药学]